The massive aircraft leasing arm of American International Group Inc. filed for an initial public offering Friday, Sept. 2, part of the insurer's plan to dispose of assets to repay its U.S. government bailout.

New York-based insurer AIG would initially sell 20% of ILFC Holdings Inc. in the offering, with plans to divest much of its remaining stake over time. Citigroup Inc., J.P. Morgan Chase & Co. and Morgan Stanley are listed as underwriters on the offering, with John-Paul Motley of O'Melveny & Myers LLP representing the company and James J. Clark and William J. Miller of Cahill Gordon & Reindel LLP serving as underwriter counsel.

The company's filing with the Securities and Exchange Commission includes only a placeholder offering size of $100 million. AIG chief executive Robert Benmosche last month said that he believed ILFC was worth at least $8 billion, implying the offering could raise at least $1.5 billion.

ILFC, of Los Angeles, ranks as the world's largest independent aircraft lessor, with a portfolio of more than 1,000 owned or managed planes as well as commitments to purchase at least 236 more. The company boasts more than 180 customers spread across 80 countries, generating net income of $143 million on sales of $2.25 billion in the first six months of 2011.

The company also has a deal in place to acquire AeroTurbine Inc. from AerCap Inc. for $228 million in cash, a deal that would provide it with in-house parts and engine-leasing capabilities.

ILFC and other lessors have benefitted from a push by commercial airlines to refresh their fleets with newer, more fuel-efficient aircraft. Airlines are increasingly focused on leasing planes instead of buying due to the lower capital outlays required, with the percentage of the global active commercial aircraft fleet under lease increasing from 19.6% in 1996 to 38.5% in 2011, according to ILFC data.

AIG has long-listed ILFC as one of its assets marked for divestiture to help repay the $180 billion bailout it received in 2008 during the financial crisis. But the company has had little luck selling the business, with a 2009 auction that attracted significant interest from private equity ending without a transaction.

ILFC was formed in 1973 as International Lease Finance Corp. and was acquired by AIG in 1990. For most of its history it was run by Steven F. Udvar-Hazy, who retired in February 2010 and in April of this year took ILFC rival Air Lease Corp. public in a $802.5 million offering.